Mission MC2 Impulse and Momentum Change
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A 2.0-kg object moving at 5 m/s encounters a 30-Newton resistive force over a duration of 0.10 seconds. The momentum change (magnitude only) experienced by this object is approximately ____ kg•m/s.
(Note: Numbers are randomized numbers and likely different from the numbers listed here.)
When a force is exerted upon an object in a collision, the object is said to have encountered an impulse. The impulse is simply the mathematical product of the force exerted on the object and the amount of time over which it was exerted. The impulse changes the object's momentum and is equal to the amount of momentum change.
or
F • t = m • Δv
This question is quite simple if you approach it with a confident understanding of momentum change and its relationship to the impulse encountered by an object. In a collision, an object changes its momentum; that is, it speeds up, slows down, and/or changes its direction. This momentum change is caused by and is equal to the impulse that it experiences. The momentum change can be calculated in one of two ways. It is calculated as the mass multiplied by the velocity change (m•Δv) or as the force multiplied by the time (F•t). In answering this question, ask yourself what is known - mass and velocity change or force and time. Then pick the method for calculating the momentum change.
